Air-actuated switch



y 9, w. KEISER I AIR ACTUATED swr'rca Filed Match 14, 1925 i T k n fi :m a 0 5 irl i c r 3 r W rd W tion of air is occurring.

Patented Jul 9, 1929.

UNITED STATES I 1,720,180 PATENT OFFICE.

WALTER KEISER, OF ST. LOUIS, MISSOURI, ASSIGNOR TO THE AIR CONDITIONING AND ENGINEERING 00., OF ST. LOUIS, MISSOURI, A CORPORATION.

AIR-ACTUATED SWITCH.

Application filed March 14, 1925. Serial No. 15,558.

My invention relates to electric switches and more particularly to such as are air actuated. The object of my invention is to provide an electric switch which is adapted to be actuated or operated by the motion or pressure of the air in the ducts or air passages of a ventilating'system.

Another object of my invention is to provide an air actuated switch which is adapted to control the apparatus, used in ventilating systems of the recirculating type, for generating or providing the purifying agent, and which will automatically initiate the operation of that apparatus so that the purifying agent will always be present when recircula- A further object of my invention is to. provide a device for a" ventilating system which will insure automatic operation of the apparatus which furnishes the purifying agent, as soon as air moves or a pressure is setup in the ducts or passages of the system.

My invention consists in the novel construction and arrangement of parts hereinafter fully, clearly, and concisely described, clefinitely pointed out in my claims and illustrated by the accompanying drawings, in which Fig. 1 is a side elevation of my device which comprises a lever having an air vane mounted on the power arm and a tube, containing contacts and a fluid adapted to electrically connect said contacts, mounted on the work arm. The tube and its elements may be protected'by a suitable box or case not shown. Fig. 2 is a front elevation of my de-- to'insure positive functioning of the convice.

In the drawings 4 is a support which may be the top of a box or guard, not shown. This box is used to protect the contact making element of my device and which is hereinafter fully described. To this support I attach a bearing block 5 by means of screws'6 and 7, oppositely disposed relative to a lever 9, and which are adapted-to -co-act with suitably threaded openings in said bearing block and project therethrough, the block being fixedly held in position by the lock nuts 8. This bearing block is provided with a suitable opening for thereception of the lever 9 which is supported by a pin or other suitable device 10, attached to the block and used as a fu1- crum. By preference, the lever carries, at one end, a vane 11 which is so positioned that it will respond readily to very slight air pressure or movement and cause the lever to pivot or move on its fulcrum. This vane may be fixed to the lever in any suitable manner as by the bolts and nuts shown in the drawings. To the other end of the lever I attach a counterpoise or weight 12 and position the weight so that its centre of mass is offset relative to the longitudinal axis of the lever and substantially in the plane of travel of said lever. The

obvious that the tube may be mounted in any 7 suitable manner on the counterpoise.

counterpoise 12 through the lever 9. By preference, the travelof the counterpoise is limited and regulated by a suitable adjustment of the screws 6 and 7 which preferably come in contact with the counterpoise as shown in Fig. 1 of the drawings.

At one endof the tube 13 are contacts 16 and 17 adapted for connection. by the wires or. pigtails 18 and 19, to the electric circuit which is to be controlled. The tube contains a slug of mercury 20 used for making electrical connection between said contacts. In order tact making and-breaking element of my device, I preferably position the tube 13 so that it will be inclined in both the rest and operative positionsof my device. By positioning the tube on the counterpoise so that the axis of the tube is at right angles to the axis of the-lever, an inclination of the lever causes an inclination of the tube and a collection of the fluid at one end thereof.

In Fig. 1 the solid lines show the vane,- lever, counterpoise and tube in rest position, and the dotted lines show those elements in the operative position, the fluid being in connection with the contacts 16 and 17. The operation of the switch is as follows: Pressure of air against the vane 11, moves the lever 9, counterpoise 12, and tube 13, to the position shown by dotted lines in Fig. 1. In this position the tube 13 is inclined so that Movement of the vane is transmitted to the the contacts 16 and 17 and the fluid 20 are at the lower end. The liquid in the tube then makes electrical connection between the contacts. W hen the pressure is released the counterpoise 12 moves the lever and tube 13 to the rest position shown by solid lines in Fig. l, in which position the contacts 16 1?! are at the higher end of the tube and fluid 20 at the lower end In this position the electricaliconnection is broken,

1 claim;

1. In an air flow controlled. device, a hermetically sealed electric fluid switch, and means associated with the switch and adapted to be actuated by air motion to make an. electric circuit and a unitary counter-weight assembly including said switch and forming a support and an abutment therefor, said counter-weight assembly being adapted to oppose the actuation of said air actuated means and to open an electric circuit when said air 1no tion ceases.

2. An electric switch operating meansin-F ma iec passage of a ventilating system and a switch assembly comprising hermetically sealed con tacts, fluid means adapted tohe operated by movement of said element to electrically connect said contacts, a counterpoise including said switch assembly in a unitary structure, and forming a support and an abutment for said switch assembly, said counterpoise being? adapted to operate said means to open said switch.

3, In an air flow controlled device, an electric switch, including hermetically sealed contacts; a vane, a lever actuated thereby, an en closure for said switch, including a wall member forming a support for said lever, a unitary counterpoise structure attached-to said lever and including the switch contacts and fluid means adapted to electrically connect the contacts of said switch, and aloracket and positioning means for the switch, forming a part of said counterpoise structure.

WALTER KEISER. 

